Self-tuning polyharmonic damper



P" 1946. s. A. RUBISSOW SELF-TUNING POLYHARMONIC DAMPER 3 Sheets-Sheet 1Filed March 8, 1941 B A 2 M A 2 2 4 OJAJ 0 2 7% Z m z. a

L A. R}, 1 2

INVENTOR.

April 16, 1946. G. A. RUBISSOW ,7

, SELF-TUNING POLYHARMONIC DAMPER Filed March 8, 1941 :5 Sheets-Sheet 2April 16, 1946.

G. A. RUBISSOW SELF-TUNING POLYHARMONIC DAMPER Filed March 8, 1941 3sheets sheet 3 IN VENT OR.

Patented Apr. 16,1946

UNITED STATES PATENT OFFICE 2,398,722 SELF-TUNING roLYnAnMomc-nmm GeorgeAlexis Rubissow, New York, N. Y.

Application March 8, 1941, Serial No. 382,383

' 7 Claims. (01. 74-514) f This invention is particularly applicable tothe polyharmonic dampers as described in the Salomon patent applicationsNos. 333,561 and 335,081, in which the following formula is given forthe tuningcondition calculation of a dynamic damper for a predeterminedharmonic order n:

m.a.D.OK K

(theoretically for infinite inertia).

(theoretically for infinite inertia).

For obtaining fictive inertia, infinite and positive (in reference toharmonic n) R 1 m.a.D.OK Q I 2n Mp .d.l.02 For obtaining fictiveinertia, infinite and negative in reference to harmonic n) For obtainingother values for the fictive inertia (nil, positive or negative) (oftenin line motors), it is necessary to give other values to (Rz-T) Figures1 and 2 of this application show afront view and'a cross-sectional sideview. when regarding the engine rotating in the direction of the arrowF. It is very important, in all calculations of this condition ofdirection, to place the restoring levers so that while they turn in thedirection of the rotation of the driving shaft, the center of gravity ofthe restoring lever, when pivoting, approaches the axis 0 of this shaft.

The above and further objects and novel feaits of the invention.

Fig. 1 shows a schematic plan view with parts broken out, of oneembodiment of a damper partly in cross-section.

Fig. 2 is a. cross-sectional view 2-2 of Figure 1.

Fig. 3 represents diagrammatic plan views partly in cross-section, withparts broken out, of a.

damper.

Fig. 4 is a diagrammatic side view. with parts broken out, of arrestingmeans for the controlling weight controlling the position of theeccentric bushing-bearing member.

Figs. 5, 6 and 7 represent plan views, partly in cross-section, withparts broken out, of diflerent arrangements of eccentric bushing-bearingmembers. v

Figs. 8 and 9 represent plan views partly in cross-section with partsbroken out of the lever provided with eccentric bushing-bearing membersand additional weight, controlling the position of the center of gravityof the said lever.

Fig. 10 represents a cross-sectional side view, with parts broken out,of another embodiment of a part of a damper.

Figs. 11 and 12 represent, schematically, crosssectional side views ofan eccentric bushing-bearing member mounted in a lever or the like.

Figs. 1 3 and 14 are schematic plan views partly in cross-section, andwith parts broken out, of eccentric bushing-bearing member provided withweights for controlling their position.

Figure 1 shows a damper having a member S rigidly afiixed to the drivenor driving shaft or to'any other rotatable part of any machine. Thismember S may have any shape or form. In Figures 1 and 2, the member S isrepresented in the form of a circular flywheel, for purposes ofconvenience. On the said member S is mounted an oscillating mass T whichis able to freely move around the shaft on which the member S is tureswill more fully appear from the following mounted. If desired, a bushingmay be provided on the member S on which the oscillating mass T ismounted, preferably concentrically. This bushing is not shown on thedrawings. If desired, a ball-bearing, needle-bearing, cylinderbearing,etc. may be employed. The mass T is shown mounted concentrically inrelation to the center 0 on Figure 1, and in relation to the axis XX ofFigure 2. However, the member S may be provided with an eccentricbushing in relation to the axis (not shown on the drawings, beingself-explanatory), in which case the opening of the oscillating mass Tmay also be eccentric to the axis XX. 1

The restoring member or levers L may be one or two symmetrically placedlevers as shown in Figures 1 and 2, or any number of levers. Each leverL is provided with an opening or 'arcuate runway 24. The oscillatingmass T is provided with an opening or arcuate runway 26. The mem: her orlever L is operatlvely interconnected with the oscillating mass Tthrough. the intermediary of a pin or roller 28. The member or lever Lis further provided with a circular opening A25! in which a pivot axle30 is mounted, so that the lever may rotate limitedly around it. Thepivot axle 29 or A may be afilxed either rigidly or rotatably in themember S, for instance, by its ends 29--I and 29-2, as shown in Fig. 2.

The operation of this device has been fully described in the said twoSalomon applications, Polyharmonic dynamic dampers, Serial Nos. 333,561and 335,081.

One aspect of this invention comprises providing the lever L with aneccentric member A2 having an interior circular opening 29A1 in which,or through which, the pivot axle 29 or A passes and which serves as abushing or as a bearing for the said pivot axle. The outer circumferenceof the eccentric member A: is eccentric in respect to the center G ofthe pivot axle 29. The eccentric member A2 should preferably have itscenter of gravity GAz on the radius R5 passing through the centers andC. The centrifugal force will thus urge the eccentric member A: intosuch a p sition that its center of gravity GA: will lie on the radiusR5. Should the eccentric member A2 for any reason be moved from theradius Rs, its center of gravity GAz will force it to return to itsnormal position. An arrangement such as this will permit the lever L topivot around the pivot axle 29 or around the outer circumference ofeccentric member AaE, or simultaneously around both, or first partlyaround pivot axle 29 and then around eccentric member AzE, or viceversa.

Owing to the fact that the harmonic order 11 also depends upon thedistance d as per the formula herein given, any change in d either byway of being augmented or diminished, would change the harmonic order.This distance d is equal to WK1 as shown on Fig. 1 (assuming W on theperpendicular at K2 to 0K2).

It is evident that the action of the lever L will also depend on thepossibility it has of rotating around the outer circumference AzE of theeccentric member A2, 1. e., around the axis passing through the centerCA2, namely, rotate around another point W1 instead of CA2, thusaugmenting the distance d in the arrangement as shown in Fig. 1, ordiminishing the distance d if a suitable arrangement will be provided.This arrangement increases the polyharmonic tuning efficiency of thedevice herein described, and enables it to take care of severalharmonics simultaneously. s a rule, in an engine with harmonic orders of5 /2, /2, '7 or 8, for example, this invention will first take care ofthe harmonics for which it is designed by choosing the relation betweenthe pivot axle 29, the pin 26 and the runways provided for the pin, andthereafter with the assistance of the eccentric member A2, will takecare of additional harmonics as well.

This invention comprises valuable improvements on the subject of thebefore-mentioned applications, providing an automatic control for theposition which adjusts the polyharmonic damper of the character referredto, tea. given order. Such automatic control utilizgsjhelallation-of thecentrifugal force provided in the damper during its rotation atdifierent speeds.

One of such improvements comprises means rigidly affixed to at least oneof the eccentric bushing-bearing members, such means beinga weightrigidly attached to said bushing-bearing members at a sufllcientdistance from their center of rotation, or mounted in saidbushing-bearing members eccentric to their center of rotation, so thatwhen the centrifugal force increases, the said bushing-bearing memberswill be urged by the centrifugal force created by the said weight. Whenthe centrifugal force increases with the increase of the speed ofrotation, it displaces the said weights and also turns the saideccentric bushing-bearingsfrom one position to another, changing therebythe tuning conditions controlling the movement of the lever relativelyto the shaft and to the other components of the damper.

One of such arrangements is schematically illustrated in Fig- 3, whereinthe lever L is pivoted on a pin I00 on whichthe eccentricbushing-bearing member IllI is mountedfeither rigidly or rotatablyaround it. 'An arm or pivot means I02 connects the eccentric member IIJIwith the weight I03N1. The lever LN1 of such a polyharmonic damper isshown in dotted lines by LN in Fig. 3, in its non-operative position.Accordingly, in such a position the center IMN of the eccentricbushing-bearing member IUIi also shown in dotted lines, may be so chosenthat prior to the rotation of the damper it takes the position as shownin Fig. 1, and as soon as the rotation of the damper begins, this centerIMN respectively takes a new position, for example, the position lll lm(Fig. 3); because of the weight was (shown in dotted lines) being urgedby the centrifugal force from its position I03N to the position I03N1.It is advisable to provide the arm or pivot means I02 with resilientmeans I06 attached to a support I01 which may be rigid with the flywheelmass S of Fig. 1 or may be rigid with the free oscillating mass T ofFig. 1, or may be rigid with the lever L itself, as shown in Fig. 14.Such resilient means may be a spring I06 or a rubber, or a mixture ofspring and rubber, or may be a pneumatic arrangement such as I08 forinstance, as shown in Fig. '7. Instead of one spring, several springsmay be employed simultaneously, operating by pull or push, or both.

One of the important aspects of this invention is the appropriate choiceof the length of the arm I02, and of the value of the weight Hliim andof its shape and form.

From the aforementioned formula, the tuning order n.is directlyproportional in certain relations to a and D, or only a or only D, andis in reverse proportion to d (i. e., if the 12 order is increased).Should all other symbols of the formula remain the same, then:

(1) When 11 increases, a decreases, or

(2) 12 increases and D increases, or

(3) 11. increases, a and D both increase, or

(4) 11, increases, d diminishes, or

(5) nincreases, It increases, and d diminishes,

(6) 1:. increases, D increases, and d diminishes.

In the case that n diminishes, vice versa relations will take place.

It may happen that, simultaneously, n will increase, a will slightlydiminish, but D will au ment sufiici'ently to compensate for thediminishing of a; or, it may happen that d will diminish to compensatefor the diminishing of a. Several of when rotating at certain sucheventualities for tuning the n ordermay take place. and this inventionprovides means to automatically tune the lever L in a given damperaccording to the Order which has to be taken care 1 of, i. e.,eliminated or substantially eliminated at corresponding speeds.

It is not feasible to describe all the movements of the components ofthe damper necessary for accomplishing these results, and by wayof,example,'the most characteristic one will be given.

In Fig. 3, the lever LNI is shown in its operative position in dottedlines LN, in which position it is maintained when the center I04N1 ofthe eccentric bush-bearing member IOI lies on the radius RNi. Theeccentric bushing member may, by way of example, be composed (as shownin Fig. 2) from'an axle 29-I, 29-2, on which the eccentricity makingmember 30 is mounted eccentricity making member 30. When 30 is rigidwith the axle 20-I, 292, then the lever I02 may be mounted either on themember 30 or on g the axle 29-I, 29--2. When the member "30 is not rigidwiththe axle 20 -I, 29-2, then the lever I02 should be mounted rigidlyon the member 30.

In its non-operating position, and the lever I02 to which a weight I03N1is attaohed occupy positions as shown in Fig. 3, such respectivepositions of lever LNl and lever I02 being controlled in particular bythe position of the center of pivoting 504 of the eccentricity makingmember 30 around which the lever LNl is able to pivot. v

The corresponding position of 504, for instance, will lie on the radiiRNl, when the lever I02 is in its lowest position as shown in Fig. 3.

The lever I02 may be provded with a weight |03N1 and resilient means I06operatively interconnecting the lever I02 through the attachment II1with the attachment I01 rigid with the member S mounted rigidly on themain shaft 505 as shown in Fig. 3.

When the damper rotates with various speeds, the position of the weightI03N1 will entirely depend on the resilience of the resilient means I05the lever LN! he of any liind and nature and, for instanc resilientblade spring 501 or an arrangement a: shown in Fig. 4, comprising asupport on which a lever H2 is mounted on a pivot I I3, the other end ofsaid lever also having a pivot III on which is mounted another lever II0. The pivots and 1evers may be so arranged that when the weight I03 Ncontacts the lever IIO, it will compress the spring II4 having apredetermined resiliency to correspond to the centrifugal force to whichsuch weight I 03N will be subjected when it contacts the lever iln atpredetermined R. P. M. of the damper. Thus, only after the resiliency ofspring I I4 will be overcome could the weight I03N pivot the levers H0and H2 and occupy the position I I03N2 for instance.

shown in Fig. 4 may be placed alongthe pathway 506 and may thus controlmore precisely the position of the lever I02, which will rest on suchposition-controlling means for as long as the corresponding R. P. M. ofthe damper will not exceed the predetermined ranges of value.

Thus, by way of example, at certain R. P. M., the pressure exercised bythe weight I03N on the position-controlling means I09 may, for instance,be 140 pounds. Should we provide the resilient means of the blade spring501, Fig. 3, or of the resilient means I I4 of Fig. 4 to be greater than140 pounds, say for instance 155, then the weight I03N and also thelever I02 will rest on such spring until the R. P. M. will be so bigthat the and will take, for instance, the position I03Ni,

speed.

When non-rotating, the resilient means I06 will pull the lever I02 intothe position I03N.

Thus, the center of pivoting 504 will respectively occupy the positionfrom I04N1 to I04N2 to I04N, whereby the distance DN (i. e., theperpendicular from center 504 to the center of gravity GN of the leverLNi) DNl, displacing respectively, the center of gravity GN to theposition GNI, GNz, and so on.

The difference between DN and DNl, and so on, may thus be controlled bythe angular displacement of the weight I03N1 and of the lever I02 inregard to the center of pivoting 504 and thus, in order to provide aself-tuning damper, it will suffice to make such respective positions ofthe center of pivoting 504 and center of gravity GN correspond to thevalue 111 in the tuning equation, such as given herein.

On its way from the position I03N to the position I03N1 (i. e., from theposition of rest of the damper to the position when it rotates at acertain speed) the lever I02 and the weight I03N will follow apredetermined pathway, for instance, 508 on Fig. 3. l

It will sufllce according to this invention, to provide means I09 asshown in Fig. 3, which may will change from DN to I centrifugal pressurewill become equal to 155 pounds. This is extremely important to preventthe undesirable pivoting or the lever I02 durin the R. P. M.corresponding to the given centrifugal forces of -155, given purely forexample only. It should be noted that such arrestingposition-controlling means as I09 and 501, Fig. 3, or as shown in Fig.4, may be attached either to the member ,8 or to the member T of Fig. 3.This requires only a reasonable skill of engineering.

The eccentric bushing-bearing members 30, 29I, 292, may be provided asshown in Figs. 1, 2 and 3. In Figs. 5, 6 and '1 the ccentric I I8 may bemounted either around 28 or B,- or around the pin A (Fig. 2), or. aroundboth of them simultaneously. Such an arrangement is shown by around Aasshown. However, the pin B may also be provided with one or two of sucheccentries as shown in Figs. 11, 12, 13 and 14.

Instead of resilient means I06, a spring-blade or the like I23 (Fig. 8)may be used if affixed rigidly by attachment I24 to the lever (or to theflywheel mass S or to the oscillating mas T) and contacting by its freeend I25 the attachment I26 rigidly affixed to the arm I02 to which theweight I03N1 is attached. Such type of spring I23 may also be employedwith one end I21 (Fig. 11) attached directly to the pin A (or B) throughsuitable means I24-I, its free end I 25-I resting on attachment meansI28 rigidly ailixed to the eccentric member A1 or B1.

The initial position of the eccentric bushingbearing member A1 or B1 asshown on Fig. 5,

may be so chosen that by movement of the weight I29: to a position I28mthe center around which displacement; a displacement, for example, alongthe radius passing through the center (Fig. 3) of the rotation of thedamper.

The eccentric members, as shown in Figs. 13 and 14, may also be employedif desired. In this case, the eccentric I33 cooperating with the pin Bwill be mountedin the lever L or flywheel mass or member S oroscillating mass T, and may be provided with arms or with weights I34 tocontrol its positions. At the same time, the other eccentric members forthe pin B may be either a simple opening I35 a shown in Fig. 9, or itmay be an eccentric bushing-bearing member I36 (shown in Fig. 13),controlled by a special arm I39, together with the weight I31, ifdesired. Tuning of the lever may be controlled only by the weight I34 ofthe eccentric I33, in which case the arm I38 may be connected with thearm I39 through the intermediary of pivoted lever I48 or otherarticulated or flexible interconnection.

Still another embodiment of this invention is demonstrated in Figs. 11and 12, wherein the eccentric members A1 or B1 are provided with arms MIand the lever L (or T or S respectively) are provided with a slot I42through which the arm I4I may pass. Such arrangements are particularlyadvantageous for economy of space.

Another important feature of this invention is to provide operativeinterconnection between the arms which operate the bushing-bearingmember of the same dampers. For instance, in Fig. 9, the weights I2I andI22 controlling the eccentrics A and B, are operatively interconnectedthrough articulated means I64 which are pivoted on pivots I65, I66. Anynumber of such articulated interconnections may be used to coordinaterelative displacements\ of one bushing-bearing in relation to others.

Still another aspect of this invention is illustrated in Fig. 3A whereinthe lever Lu is provided with a cutout I46 in which a mass I4! ismounted so that it can freely move along the said cutout. The lowersurface of the cutout may follow a circumference I48 made with a radiusfrom the center 0 or with any other suitable radius. The position of themass I41 in the cutout I46 will vary the position of the center ofgravity GN of the lever LN1. The mass I41 may be provided with means tocontrol its position mechanically, hydraulically, pneumatically,electro-mechanically, or electro-magnetically, depending upon the speedof rotation of the device. These means may be operated voluntarily orautomatically. Such automatic means consist of an arm I50 with a weightI49n affixed to a gear I5I mounted on a shaft I52, which is mounted onthe lever Lm. When the weight I49: moves into the position I49m it movesthe mass I41 from its original position (shown by dotted lines) to theposition as shown in solid lines by I41 in Fig. 3

and corresponding to the position I49m of the lever I50. Resilient meansI53 may be provided to control the displacement of the mass I41 and topush it back when the damper reduces the speed or stops. 6 In addition,resilient means I64 may also be provided to establish an opposing.

new position Gm, thus augmenting the distance Dm to the distance Dm fromthe pivot A1. The proper choice of augmentation or diminution of suchdistance will correspondingly influence the characteristics of thedamper and thus take care of the harmonic or other disturbancescorresponding, for instance, to the position of the center of gravity ofBus or any other intermediate positions between Du: or between Du.

The mass I41 may also have the form of a cylinder I5|, as depicted inFig. 8, mounted in a cylindrical cutout I58 provided with resilientmeans I58. The inclination of the longitudinal axis of the cylinder I58may be so chosen that there will be sufiicient forces provided tocontrol the displacement of the weight I5'IN from its normal positionI511: to its operating position 151m.

In Fig. 9, this cutout may be ,cylindrical or have any other shape, forinstance, I60, and follow a circumference made by the radius I6I drawnfrom the center I62, eccentric to the center 0 of the rotation of theshaft. The choice of this eccentricity gives the desired sensitivity forthe displacement of the weight, taking into consideration the resilientmeans I63, which may be spring, pneumatic, hydraulic, orelectro-magnetic. 1

In the case of controlling the center of gravity of the lever L by meansof the displacement of the masses and weights such as I41 and I49N (asshown in Fig. 3A), all desired predetermined positions of centers ofgravity of the lever Ln may be predetermined accordingly andsynchronized with predetermined speeds.-

Still another aspect of this invention consists of providing, in thedamper described, the lever of the type described, with self-adjustableweight of the type described herein for Figs. 8, 9. The

arrangement such as the lever of Salomon provided with thefree mass ofRubissow consists of providing in the mass of such lever, a cutouthaving a cylindrical or a square cross-section for example, at a certainangle a in respect to the tangent to, which is perpendicular. to theradius r. The angle a may be very small and its choice dependent uponhow much the chosen influence of the centrifugal force at certain speedsmust displace the weight towards the part of the cutout which is at afurther distance from the center of rotation of the damper than theformer position of the weight in the same cutout. A spring I59 (Fig. 8)or I63 (Fig. 9) must be placed in the lower end of the cutout. Duringrotation of the damper, the spring is compressed by the weight to apredetermined degree, thereby controlling the position of the weight inthe cutout at all speeds of rotation. The displacement of the positionof the weight in the cutout permits the displacement of the damperscenter of gravity from one position to another, and while this isaccomplished automatically, as a function of the speed of the rotationof the damper, the automatic tuning capacity of the lever is thereb alsocontrolled. Appropriate choice of the cross-section of the cutout, itslength, the angle a, value of the weight and the force of the springwill be i r 2,898,722 necessary for proper control of the automatictuning of the lever.

These arrangements may be employed without simultaneous use of theeccentric bushing-bearing member as described in thi application, Thecutouts may be of any shape or form and their longitudinal symmetry axismay also follow a circumference of a radius I62 (Fig. 9), for instance,which is concentric to the radius r. The angle a between thecircumference of the radius I62 and the circumference of the radius rmay be considered similar to the angle a of Fig. 8.

The movement of the weight may be towards the free end of the leverasshown in Figs. 8 and 9, or towards the center of the gravity of thelever. If desired, several cutouts may be employed simultaneously withside of them.

The resilient means, instead of being as shown in Fig. 8 and Fig. 9, mayalso be on both sides of the weight, one working as compressor and theother as a depressor. Only compressor or only depressor resilient meansmay be employed. Resilient means may be replaced by pneumaticpiston-cylinder arrangement.

Another aspect of this invention provides a combined use of thedescribed eccentric bushingbearing member with or without arms, or withseveral weights placed inr tion. A synchronized speed-control device maytalsii be employed if desired, for automatic con- This invention isparticularly important, inasmuch as it permits the tuning of thisparticular damper to any desired order or disturbing force of anynature. This latter aspect, as shown in Fig. 15, may be applied directlyto the bushingbearing members A or B or A1, A: etc., or B1, B2 etc., ordirectly to the arms or means which control the position of the centerof gravity of the lever. lhis means mayalso be applied in combinationwith automatic controlling means for the eccentric bushing-bearingmembers as herein described, in which latter case, their au v tomatismwill be controlled manually or by a synarms and weights, by operativelyinterconnecting such eccentric bushing-bearing members with theaforesaid weights of the character of weights or masses I41, I51N. Thismay be effected particularly by means of rigid interconnections, such asI64, Fig, 9, interconnected through the pivots I65 and I66, to theWeights I44 (or directly to the eccentrics A and B, not shown on thedrawings), or through pulley and flexible connections, gears, chains,caterpillar and the like.

Still another embodiment is illustrated in Fig. 14, having, in additionto the eccentric bushingbearing member B, a cylindical bearing I61 whichis mounted in a bushing I68 provided in the lever- L. Such cylindricalbearing I61 will permit the pin B4 to rotate while it'is urged left orright, thus diminishing tangential frictional effort be tween thecontacting surfaces of displacing parts.

Another, and one of the most important aspects of this inventionprovides voluntary consimultaneous use of the eccentric bushing-beartrolof the position of the eccentric bushing-bearing members. This isaccomplished by an arrangement of levers, flexible interconnections, ar-

ticulated means, pneumatic cylinder-piston devices, electro-mechanicalor electro-magnetic means, with a collar-like member mounted on a shaftin such a way that when Pushed to and fro longitudinally along theshaft, the position of the said bushing-bearing members is controlled.This voluntary control enables the operator of the engine to tune thedamper at a given speed to a given sensitivity in advance, thuseliminating the undesirable torques or vibrations. This is extreme- 1yimportant and applicable to all engines where chronized controllingdevice. This aspect permits the varying of the tuning of a resonancedamper of the type described herein during the operation of the engineitself.

Fig. 15 represents the mass S (which may also be the free oscillatingmass T or the lever L itself) in which the pin 463 rigid with theeccentric bushing-member 464 is mounted. A rigid arm 465 and a smallaxle 466 are rigidly affixed to the pin 463 or may be directly affixedto the eccentric 464 itself. A rigid connection in the form of a wire,bar, arm, chain or flexible cable 461 operatively interconnects the axle466 with the pivot lever 468 which may be of any shape or form. Suchinterconnection is establishedby means of a pivot 469 or other suitableequivalent means, and by means of a pivot I16 on which the lever 468pivots. The pivot I16 is mounted rigidly in respect to the shaft I1I bymeans of a girdl I12 rigidly attached to the said shaft.- When thedevice rotates, the centrifugal force urges the arm 461 in the directionof the arrow I13. A controlling non-rotatable device I14 comprising a,preferably, well-polished plate or disk is'mounted on a girdle or collarI15, provided on shaft HI and able to slide to and fro thereon, guidemeans I16, one or more, may be provided in the frame, I11, which isrigid with the foundation or the ground or the chassis. When thecontrolling device "4 i pushed to and fro, it contacts the lever 468 inthe surface I18 which surfac itself i in constant contact with the diskI14 because of the rotation of the lever 468 with the shaft HI andbecause of absence of rotation of the disk I14. By pushing the disk toand fro, the arm I61 of the lever 6I8,control s the position of theeccentric I64 to the desired value,

thus controlling. as herein described, the characteristics of the damperand it tuning to the ap tary control by the operator, of the position ofthe eccentricmembers A1 and/or B1, and/or of the position of the centerof gravity of the lever or levers.

3. Dampers which consist of automatic control of the position of theeccentric member A: and/or B1 bymean of automatic synchronizedspeed-controlling or speed regulating devices, such as described herein.

4. Dampers using a pneumatic control of the position of the eccentricmembers A1 and/or Bl or of the weights I41.

trically to the axis of the latter, a lever mounted.

. for oscillation about said pivot means eccentri- Having nowascertained and described the" nature of the said invention and themanner in which it is to be performed, I declare that what I claim isthe following:

1. A vibration or oscillation damper for a machine shaft comprising afirst member rigidly mounted on said shaft, a second member mounted formovement about the axis of said shaft and said first member, at leastone pivot means oscillatably mounted on said first member eccentricallyto the axis of the latter, a lever mounted for oscillation about saidpivot means eccentrically to the axis of said pivot means and the centerof gravity of said lever, a. first arcuate runway in said lever, asecond arcuate runway in said second member, a pin of a radius smallerthan the radius of curvature of either of said runways operativelyconnecting said lever with said second member, a solid weighteccentrically secured to said pivot means, resilient means adapted toresist movement of said-weight in response to centrifugal force, saidDivot means, weight, and re-.

silient means cooperating to shift or adjust the ivot point of saidlever relative to the center of gravity of the lever in response tocentrifugal force, thereby tuning said damper to various orders ofvibration.

2.v A vibration or oscillation damper for a machine shaft comprising afirst member rigidly mounted on said shaft, a second member mounted formovement about the axis of said shaft and said first member, at leastone pivot means oscillatably mounted on said first member eccentricallyto the axi of the latter, a lever mounted for oscillation about saidpivot means eccentrically to the axis of said pivot means and thecenresilient means cooperating to shift or adjust th pivot point of saidlever relative to the center of gravity of the lever in response tocentrifugal force, said damper further comprising means forsupplementing or increasing resistance to movement of said weight inresponse to centrifugal 'force, said supplemental or increasedresistance being applied at a certain point or at certain points in thepath of movement of said weight,

thereby tuning said damper to various or ders' ofvibration.

3. A vibration or oscillation damper for a machine shaft comprising afirst member rigidly mounted on said shaft, a second member mounted formovement about the axis of said shaft and said first member, at leastone pivot means oscillatably mounted on said second member eccencally tothe axis of said pivot means and the center of gravity of said lever, afirst arcuate runway in said lever, a second arcuate runway in saidsecond member, a pin-of a radius smaller than the radius of curvature ofeither of said runways operatively connecting said lever with saidsecond member, a solid weight eccentrically secured to said pivot means,resilient means adapted to resist movement of said weight in response tocentrifugal force, said pivot means, weight, and resilient meanscooperating to shift or adjust the pivot point of said lever relative tothe center of gravity of the lever in response to centrifugal force,thereby tuning said damper to various orders of vibration.

4. A' vibration or oscillation damper for a machine shaft comprising afirst member rigidly mounted on said shaft, *a second member mounted formovement about the axis of said shaft and said first member, at leastone pivot means oscillatably mounted on said second member eccentricallyto the axis of the latter, a lever mounted for oscillation about saidpivot means eccentrically to the axis of said pivot means and the centerof gravity of said lever, a first arcuate runway in said lever, a secondarcuate runway in said second member, a pin of a radius smaller than theradius of curvature of either of said runways operatively connectingsaid lever with said second member, a solid weight eccentrically securedto said pivot means, resilient means adapted to resist movement of saidweight in response to centrifugal. force, said pivot means, weight, saidresilient means cooperating to shift or adjust the pivot point of saidlever relative to the center of gravity of the lever in response tocentrifugal force, said damper further comprising means forsupplementing or increasing resistance to movement of said weight inresponse to centrifugal force, said supplemental or increased resistancebeing applied at a certain point or at certain points in the path ofmovement of said weight.

5. A damper as set forth in claim 1 wherein said pivot means comprises apivot-axle and an arm attached rigidly thereto, clearance means beingprovided in said second member around said pivot-axle to permit themovement of said second member around the axis of said shaft.

6. A damper'as set forth in claim 3 wherein clearance means are providedin said first member around said pivot-axle to permit the movement ofthe said second member and said pivotaxle around the axis of said shaft.

7. A damper as set forth in claim 2 wherein said means for supplementingor increasing resistance to the movement of said weight in response tocentrifugal force comprises at least one articulate member havingresilient opposing means and mounted in the path of movement of acontact member rigidly attached to said weight to resist the movement ofsaid weight as it pivots around said pivot means in response to saidcentrifugal force.

GEORGE A. RUBISSOW.

